Article Title: Investigation of coa Gene Polymorphism in Clinical Isolates of Staphylococcus aureus in North of Iran

Staphylococcus aureus is a common pathogen potentially able to cause a wide range of infectious diseases in human and animals and coagulase enzyme is one of the important virulence factors of this bacterium. Polymorphism of the coagulase encoding gene (coa) is one of the molecular-based typing methods of S. aureus isolates. In this study, the polymorphism of the coagulase gene among MRSA and MSSA isolates were investigated using PCR-RFLP analysis. To perform coagulase gene typing, the repeated units encoding hypervariable regions of coagulase gene of 30 clinical isolates of S. aureus were amplified by the PCR technique; this was followed by AluI restriction enzyme digestion and analysis of restriction fragment length polymorphism (RFLP) patterns. In total two amplicons (680 bp and 750 bp) and four distinct RFLP banding patterns (280+400, 340+340, 280+470, and no digested amplicon of 750 bp) were observed. Genotype with PCR-RFLP patterns of 280+400 bp was predominated. The results indicated polymorphism in the investigated regions of coagulase gene. This polymorphism can be used for identification of S. aureus isolates and showing the epidemiological relationship among them.